1. Field of the Invention
The present invention relates to a robot system display device for graphically displaying a robot system in order to check an arrangement relationship among a robot, peripheral equipment, and a vision sensor.
2. Description of the Related Art
There are known robot systems configured such that a robot performs work such as handling or shaping a target object based on positional information of the target object detected by a vision sensor. Vision sensors are used in various configurations in which, for example, they are disposed near a hand of the robot or on a fixed structure such as a support stand. In any case, it is necessary to identify an arrangement relationship between the vision sensor and the robot. For this purpose, it is necessary to define a relationship between a robot coordinate system as a reference for an operation control of a robot and a vision sensor coordinate system as a reference for a measurement process by way of a vision sensor. Such a process for associating different coordinate systems with each other is generally referred to as calibration of a vision sensor. The associative information obtained as a result of such calibration is referred to as calibration data.
JP-A-5-241626 discloses an exemplary calibration process for a sensor attached to a movable unit of a robot. According to this known technique, in order to calibrate a sensor before and after movement of the sensor, calibration data after the movement of the sensor is calculated based on calibration data before the movement and a movement amount of the sensor.
JP-A-4-35885 discloses a technique of calibrating of a vision sensor by using a patterned plate that is attached to a robot arm and provided with a predetermined pattern is formed. According to this known technique, it is necessary to set information such as a mounting dimension of the patterned plate beforehand. Therefore, if the information set is incorrect, inaccurate calibration data will be obtained. Not only the case of this known technique, other techniques involve setting information such as dimensions of components may be employed. Accordingly, if the information setting is inaccurate, appropriate calibration will not be carried out.
JP-A-2005-135278 discloses a simulation device for a robot system including a vision sensor and a robot. The simulation device in this known technique is used for evaluating an operation program that is created off-line. Arrangement information of the vision sensor consists of predefined values corresponding to a robot system to be simulated. Therefore, the simulation device is not designed to find an error in the calibration data for the vision sensor.
As described above, according to the conventional techniques, it is difficult to find an error in calibration data of a vision sensor even if one exists. Thus, there is a need for a robot system display device that facilitates identifying an error in calibration data for a vision sensor.